The present invention relates generally to a new wafer electrode for use in an electrolytic cell for the electrochemical production of various compounds. More particularly the present disclosure relates to an improved wafer type electrode having an access tube which is particularly suitable for use as a cathode in an electrolytic cell containing a membrane for the electrochemical production of alkali metal carbonates.
Numerous types of electrodes in the form of anodes and cathodes have been proposed for various electrolytic cells for electrochemical processes. Most of these electrodes fall within two major groups. The first group employs electrodes of a more or less cylindrical nature attached to base plates from opposing ends of an electrolytic cell and arranged in a plurality of rows and columns to provide a honeycomb of anodes and cathodes in spaced relation to each other. These electrodes are generally foraminous and made of a screen or a mesh type of material so that a diaphragm may be formed over them as may be desired for a particular electrochemical process. The geometry of these resultant cell structures makes it exceedingly inconvenient to place a planar membrane between the anodes and cathodes. Hence the second group consists of planar electrodes which may be disposed within an electrolytic cell coplanarly spaced apart in close proximity of each other allowing placement of a planar membrane therebetween. Electrodes of this type are supplied with electrical current through current distribution bars from the opposing ends of an electrolytic cell and also structurally support electrode plates. This arrangement is inadequate because precise placement of the electrodes is difficult thus resulting in certain operational inefficiencies.
Further, it is desirable to have an access port in close proximity of the electrode plate for the introduction or removal of fluids from near the electrode plate surface. In an electrolytic cell for the electrochemical production of alkali metal carbonates, for example, it is necessary to have a stream of CO.sub.2 across the cathode plate surface adjacent the membrane. This is difficult to accomplish with the present and existing electrodes as aforedescribed. Another problem which the prior art forms have failed to recognize or solve is the desirability of obtaining an even flow and distribution of the fluid across the electrode plate surface.